diff --git a/utils/fpdoc/dw_html.pp b/utils/fpdoc/dw_html.pp
index 8a9b79f5e2..a7477db238 100644
--- a/utils/fpdoc/dw_html.pp
+++ b/utils/fpdoc/dw_html.pp
@@ -255,6 +255,7 @@ type
 
     Function InterPretOption(Const Cmd,Arg : String) : boolean; override;
     Procedure WriteDoc; override;
+    Class Function FileNameExtension : String; override;
     class procedure Usage(List: TStrings); override;
     Property SearchPage: String Read FSearchPage Write FSearchPage;
     property Allocator: TFileAllocator read FAllocator;
@@ -3454,6 +3455,11 @@ begin
   List.Add(SHTMLImageUrl);
 end;
 
+Class Function THTMLWriter.FileNameExtension : String; 
+begin
+  result:='.html';
+end;
+
 // private methods
 
 function THTMLWriter.GetPageCount: Integer;
diff --git a/utils/fpdoc/dw_ipflin.pas b/utils/fpdoc/dw_ipflin.pas
index 99270533e9..f29a3e2d05 100644
--- a/utils/fpdoc/dw_ipflin.pas
+++ b/utils/fpdoc/dw_ipflin.pas
@@ -89,7 +89,6 @@ type
     procedure EndOverview; override;
     procedure WriteOverviewMember(const ALabel,AName,Access,ADescr : String); override;
     procedure WriteOverviewMember(const ALabel,AName,ADescr : String); override;
-    class function FileNameExtension: string; override;
     procedure DescrBeginURL(const AURL: DOMString); override;
     procedure DescrEndURL; override;
     // Description node conversion. Overrides for TFPDocWriter.
@@ -141,6 +140,7 @@ type
     // TFPDocWriter class methods
   public
     constructor Create(APackage: TPasPackage; AEngine: TFPDocEngine); override;
+    class function FileNameExtension: string; override;
   end;
 
 
diff --git a/utils/fpdoc/dw_latex.pp b/utils/fpdoc/dw_latex.pp
index a0c450f613..282986e66f 100644
--- a/utils/fpdoc/dw_latex.pp
+++ b/utils/fpdoc/dw_latex.pp
@@ -79,7 +79,6 @@ Type
     procedure EndOverview; override;
     procedure WriteOverviewMember(const ALabel,AName,Access,ADescr : String); override;
     procedure WriteOverviewMember(const ALabel,AName,ADescr : String); override;
-    Class Function FileNameExtension : String; override;
     // Description node conversion
     procedure DescrBeginBold; override;
     procedure DescrEndBold; override;
@@ -131,6 +130,8 @@ Type
     // TFPDocWriter class methods
     Function InterPretOption(Const Cmd,Arg : String) : boolean; override;
     Property ImageDir : String Read FImageDir Write FImageDir;
+  public
+    Class Function FileNameExtension : String; override;
   end;
 
 
diff --git a/utils/fpdoc/dw_linrtf.pp b/utils/fpdoc/dw_linrtf.pp
index 75222316e6..527c52032d 100644
--- a/utils/fpdoc/dw_linrtf.pp
+++ b/utils/fpdoc/dw_linrtf.pp
@@ -114,7 +114,6 @@ type
     procedure WriteOverviewMember(const ALabel,AName,Access,ADescr : String); override;
     procedure WriteOverviewMember(const ALabel,AName,ADescr : String); override;
     procedure EndOverview; override;
-    Class Function FileNameExtension : String; override;
     // Description node conversion
     procedure DescrBeginBold; override;
     procedure DescrEndBold; override;
@@ -162,6 +161,8 @@ type
     procedure DescrEndTableCell; override;
     // TFPDocWriter class methods
     Function InterPretOption(Const Cmd,Arg : String) : boolean; override;
+  public
+    Class Function FileNameExtension : String; override;
   end;
 
 
diff --git a/utils/fpdoc/dw_lintmpl.pp b/utils/fpdoc/dw_lintmpl.pp
index b45c81b701..9fedfb4779 100644
--- a/utils/fpdoc/dw_lintmpl.pp
+++ b/utils/fpdoc/dw_lintmpl.pp
@@ -91,7 +91,6 @@ Type
     procedure EndOverview; override;
     procedure WriteOverviewMember(const ALabel,AName,Access,ADescr : String); override;
     procedure WriteOverviewMember(const ALabel,AName,ADescr : String); override;
-    Class Function FileNameExtension : String; override;
     // Description node conversion. Overrides for TFPDocWriter.
     procedure DescrBeginBold; override;
     procedure DescrEndBold; override;
@@ -139,6 +138,8 @@ Type
     procedure DescrEndTableCell; override;
     // TFPDocWriter class methods
     Function InterPretOption(Const Cmd,Arg : String) : boolean; override;
+  public
+    Class Function FileNameExtension : String; override;
     Class procedure Usage(List: TStrings); override;
   end;
 
diff --git a/utils/fpdoc/dw_man.pp b/utils/fpdoc/dw_man.pp
index 72b9e25168..5d051cd410 100644
--- a/utils/fpdoc/dw_man.pp
+++ b/utils/fpdoc/dw_man.pp
@@ -97,7 +97,6 @@ Type
     procedure WriteCommentLine;
     procedure WriteComment(Comment : String);
     Procedure WriteExampleFile(FN : String); virtual;
-    Class Function FileNameExtension : String;virtual;
     procedure WriteExample(ADocNode: TDocNode);
     procedure WriteSeeAlso(ADocNode: TDocNode; Comma : Boolean);
   Public
@@ -178,6 +177,7 @@ Type
     procedure DescrBeginTableCell; override;
     procedure DescrEndTableCell; override;
     Function InterPretOption(Const Cmd,Arg : String) : boolean; override;
+    Class Function FileNameExtension : String; override;
     Class procedure Usage(List: TStrings); override;
   end;
 
diff --git a/utils/fpdoc/dw_template.pp b/utils/fpdoc/dw_template.pp
index e19414e74d..a535ee3ab5 100644
--- a/utils/fpdoc/dw_template.pp
+++ b/utils/fpdoc/dw_template.pp
@@ -161,7 +161,7 @@ Type
     // Provide feedback about usage of this backend.
     Class procedure Usage(List: TStrings); override;
     // For info only. See linear writer for an example.
-    Class Function FileNameExtension : String;virtual;
+    Class Function FileNameExtension : String; override;
   end;
 
 implementation
diff --git a/utils/fpdoc/dw_txt.pp b/utils/fpdoc/dw_txt.pp
index 17bc1a139b..37dc825fb0 100644
--- a/utils/fpdoc/dw_txt.pp
+++ b/utils/fpdoc/dw_txt.pp
@@ -82,7 +82,6 @@ Type
     procedure EndOverview; override;
     procedure WriteOverviewMember(const ALabel,AName,Access,ADescr : String); override;
     procedure WriteOverviewMember(const ALabel,AName,ADescr : String); override;
-    Class Function FileNameExtension : String; override;
     // Description node conversion
     procedure DescrBeginBold; override;
     procedure DescrEndBold; override;
@@ -130,6 +129,7 @@ Type
     procedure DescrEndTableCell; override;
   Public
     Constructor Create(APackage: TPasPackage; AEngine: TFPDocEngine); override;
+    Class Function FileNameExtension : String; override;
     Class Procedure Usage(List : TStrings) ; override;
     Function InterpretOption(Const Cmd,Arg : String) : Boolean; override;
   end;
diff --git a/utils/fpdoc/dwlinear.pp b/utils/fpdoc/dwlinear.pp
index c61e1deaab..d36da5b293 100644
--- a/utils/fpdoc/dwlinear.pp
+++ b/utils/fpdoc/dwlinear.pp
@@ -85,7 +85,6 @@ Type
     procedure StartUnitOverview(AModuleName,AModuleLabel : String);virtual; Abstract;
     procedure WriteUnitEntry(UnitRef : TPasType);virtual; Abstract;
     procedure EndUnitOverview; virtual; Abstract;
-    Class Function FileNameExtension : String;virtual; Abstract;
     Property LastURL : DomString Read FLastURL Write FLastURL;
   Public
     Constructor Create(APackage: TPasPackage; AEngine: TFPDocEngine); override;
diff --git a/utils/fpdoc/dwriter.pp b/utils/fpdoc/dwriter.pp
index 44e625c22a..324f3c0dbc 100644
--- a/utils/fpdoc/dwriter.pp
+++ b/utils/fpdoc/dwriter.pp
@@ -160,6 +160,7 @@ type
     Property ImageExtension : String Read FImgExt Write FImgExt;
     // Should return True if option was succesfully interpreted.
     Function InterpretOption(Const Cmd,Arg : String) : Boolean; Virtual;
+    Class Function FileNameExtension : String; virtual;
     Class Procedure Usage(List : TStrings); virtual;
     procedure WriteDoc; virtual; Abstract;
     Function WriteDescr(Element: TPasElement) : TDocNode;
@@ -350,6 +351,12 @@ begin
   Result:=False;
 end;
 
+class function TFPDocWriter.FileNameExtension: String;
+begin
+//Override in linear writers with the expected extension.
+  Result := ''; //Output must not contain an extension.
+end;
+
 Class procedure TFPDocWriter.Usage(List: TStrings);
 begin
   // Do nothing.